Player character walks through terrain and objects

I am new to unity and developing a video game as part of a project. I used a mechanim tutorial to animate my character which was imported from 3ds max. However once in unity, it can walk through any object including terrain walls and other imported game objects. “Is trigger” is turned off, the elements all have colliders, I’m really baffled as to what the problem is.

Does anyone have any suggestions?

Be sure the character has a collider as well. In the Scene view check the positioning of your character’s collider and the positioning of the colliders on the objects the character is able to walk through. When checking the positioning, look at it from all angles. Not just from the front. The best way (I’ve found) to do this is to go into isometric view. In the Scene view, the gizmo in the upper right corner has a box in the center. Clicking it swaps between perspective and isometric view. You know you’re in isometric if the gizmo has 3 straight lines under it. Then just click the various axis to swap between view angles. Do this to make sure all colliders completely encompass their objects.

Check your physics matrix settings to make sure that the character can collide with other object. Also there are difficulties with mesh colliders interacting with each other. Try prototyping with some basic unity colliders to see if that fixes your problem.